The present invention relates generally to the detection and ejection of foreign matter from crop harvesting machines and, more particularly, to a trip mechanism operatively associated with an electronic stone detection device to effect the unlatching of a trap door upon the detection of foreign matter for the ejection thereof from the feed path of the crop harvesting machine.
Generally, crop harvesting machines, commonly referred to as combines, include a crop harvesting header mounted at the forward end thereof to initiate the crop harvesting process. Normally, the harvested crop is consolidated within the header and fed to a centrally located conveying mechanism within a feeder housing. From the feeder housing, the harvested crop is fed to the combine base unit for further harvesting treatment.
It has been found desirable to eliminate non-crop foreign matter from the flow of harvested crop before it reaches the base unit for further harvesting treatment. Foreign matter includes stones, wood and other debris which can be harmful to the harvesting equipment normally housed within the base unit. Combines utilizing the rotary harvesting principal are particularly susceptible to damage from such non-crop foreign matter.
Accordingly, non-crop foreign matter detection devices, commonly referred to as stone traps, have been developed. One such mechanical detection device utilizes a pinch roller mounted a predetermined distance above a trap door such that the flow of crop material is between the pinch roller and the trap door. Non-compressible matter, such as stones, entering the crop flow between the pinch roller and the trap door and having a height greater than the distance between the roller and the trap door, is forced downwardly against the trap door to force the trap door open and eject the foreign matter. Electronic detection devices have also been developed for sensing the presence of such matter and emitting a signal receivable by an ejection mechanism to remove the foreign matter from the flow of crop.
The problem remaining after electronic detection of the foreign matter in the feed path of the crop being harvested is the provision of a mechanism for receiving the signal and tripping the release of the trap door for ejection of the foreign matter. Since a more successfully detection rate of foreign matter could be obtained if both electronic and mechanical detection devices were provided on the crop harvesting machine, it would be advantageous if the trip mechanism could interact with the mechanical detection and ejection device.